Screeding apparatus

ABSTRACT

Screeding apparatus adapted to be carried by a self propelled machine, for finishing concrete-like material to a certain degree of smoothness. The screeding unit is attached to its raising and lowering carrier from above by a floating single point at or near its forward end and by a pair of pivotally mounted bar-like members operating between the carrier and the screeding unit. Lateral movement is provided by a positioning member coupled between the carrier and the screeding unit. The screeder follows guide strips but is not carried by such strips.

United States Patent Klopf June 11, 1974 1 SCREEDING APPARATUS Primary ExaminerEdward C. Allen A F.KI fB Ct,M h. [75] Inventor dam 0p ay 1 y lc Attorney, Agent, or I-rrm-Earl D. Ayers [73] Assignee: The Dow Chemical Company, Mldland, MlCh. [22] Filed: 14, 1972 Screeding apparatus adapted to be carried by a self [21 App} No; 169,138 propelled machine, for finishing concrete-like material to a certain degree of smoothness. [52] U S Cl 404/114 The screeding unit is attached to its raising and [51] In} .Cl 1c 19/22 lowering carrier from above y a floating Single paint [58] Fieid 119 113 at or near its forward end and by a pair of pivotally mounted bar-like members operating between the carrier and the screeding unit. Lateral movement is [56] References Cited provided by a positioning member coupled between UNITED STATES PATENTS the carrier and the screeding unit. The screeder 2,372,163 3/1945 Whiteman 404/119 follows guide strips but is not carried by such strips, 2,909,970 10/1959 Jackson 3,374,717 3/1968 Reynolds 404/113 3 Claims, 3 Drawing Figures SCREEDING APPARATUS BACKGROUND OF THE INVENTION This invention relates to screeding apparatus and particularly to portable apparatus for use in resurfacing operations on roadways.

Previous self-propelled concrete finishing screed beams have been supported on end carriages that travel on rails or side forms that are set to grade. The accumulative weight of necessary equipment such as framing, motors, drive mechanisms, beams, vibrators and controls make such units quite awkward and heavy.

Also, during the operation of the above type of apparatus, the operator is exposed to adjacent lane traffic, if any.

When re-surfacing of highways, bridges or overpasses is to be done, it is desirable, if practicable, to leave adjacent lanes open to traffic so that traffic will not have to be detoured around the repairs.

When conventional screeding apparatus is used manual lifting and shoving of beams is required. This is not only time-consuming but requires that the operator(s) be exposed to adjacent traffic hazards.

Resurfacing operations often take place over small areas, too, and the lack of easy portability of the screeding equipment adds to the cost of such operations.

Further, since conventional screeding apparatus rides on rails, these rails must be moved to a new location and set in place before operation of the screeding apparatus may take place. When the resurfacing of several parts of a roadway is to be done, the operation becomes very time consuming with respect to the actual resurfacing which is accomplished.

Accordingly, a principal object of this invention is to provide improved screeding apparatus.

Another object of this invention is to provide improved, safer to use screeding apparatus.

A further object of this invention is to provide improved, easier to use screeding apparatus.

Yet another object of this invention is to provide improved, more portable screeding apparatus.

In accordance with this invention there is provided screeding apparatus including a frame adapted to be coupled to a prime mover such as a tractor having hydraulic loading means at the front thereof, for example. The generally rectangular frame is pivotally coupled at its rear part by means of a pair of spaced apart arm elements to the prime mover and has its front end supported from above by an air cylinder device cantilevered from the mounting plate for the frame. A laterally moving element coupled to the mounting plate is operatively coupled to the frame for making small lateral movement of the apparatus.

The air cylinder device has its piston position (and the lift on the front of the frame) adjusted by varying the air pressure on the cantilevered support, which functions as an air storage tank.

Screeding beams having, suitable vibrator units coupled thereto are carried by the frame.

The invention, as well as additional objects and advantages thereof, will best be understood when the following detailed description is read in connection with the accompanying drawing, in which:

FIG. 1 is a front elevational view of apparatus in accordance with this invention;

FIG. 2 is a plan view of the apparatus shown in FIG. 1, and

FIG. 3 is a side elevational view of the apparatus of FIG. 1.

Referring to the drawing, and particularly to FIGS. 1 and 2, there is shown screeding apparatus, indicated generally by the numeral 10, comprising a frame, indicated generally by the numeral 12, composed of transverse beam 14, and end beams 16, 18 coupled together to form a rigid unit. The beam 14 is coupled to the end beams 16, 18 at their midpoint, forming a generally I- shaped frame.

A pair of screeding boards 20, 22 are coupled to the frame members 16, 18 by means of bolts 24, 24a and 26, 26a. Conventional vibrator units 28, 30 either electrically or pneumatically driven, for example, are coupled to the boards 20, 22. Vibrator units 28, 30 are each disposed about half way between the ends of the boards 20, 22 respectively.

The boards 20,22 are each coupled to the frame members 16,18, through spring cushioned coupler elements 46,48 and 50, 52, respectively.

Referring also to FIG. 3, a mounting plate 32 is coupled by means of pins to the lift arms 34, 36 and 35, 37, one pair on each side of the prime mover, not shown. The plate 32 is generally rectangular in configuration and has a horizontally disposed hydraulic piston unit 38 located on its front surface with its piston rod 40 extending to the side of the plate 32. The rod 40 is coupled to an elongated rigid element 42 which is rigidly mechanically coupled to the frame member 18. The unit 38 is coupled to the plate 32 at one end by a pivotal coupler unit 44.

A frame beam 14 is basically two hollow enclosed elements joined together by a framework 54 having an open central part through which a hydraulic cylinder unit 56 extends. The hydraulic cylinder unit 56 is coupled to the framework 54 by means of pin coupler 58. The piston 60 of the hydraulic unit 56 is coupled to the outer end part of a cantilevered support member 62 which is supported at its rear end part by means of a post member 64 which is coupled in vertical position with respect to the mounting plate 32 near the center thereof.

The mounting plate 32 is also coupled to the frame 12 by means of elongated elements 66,68. Each element 66, 68 is pivotally coupled to the mounting plate 32, as at 70,72, and to downwardly extending elements 74,76, respectively (which are rigidly coupled to frame members 16 or 18) as at 78,80. The mounting of the coupling elements 66,68 between the mounting plate 32 and the frame 12 is such that the elements 66,68 are parallel with each other.

In operation the apparatus is coupled to a prime mover (not shown) such as a tractor having lift arms 34,36, 35,37. The screeding boards 20,22 are aligned with the guide elements 90,92 (see FIG. 1) which border the area to which refinishing material such as concrete, has been applied.

The guide elements 90,92 may be wooden planks which, because of their low price, are not re-shipped to each new resurfacing location but are used for other construction purposes as salvage material. Thus, the guide elements can be placed in position at any resurfacing location without waiting for the conventional type of guide rails to be disassembled, shipped and reassembled before screeding can be done.

While some part of the weight of the apparatus is carried by the guide elements 90,92, most of the weight is carried by the prime mover.

The transverse beam 14 is a hollow enclosed member (on each side of the open center part) which is a pressurizable reservoir coupled to the hydraulic unit 56 by means of the hose 94. The interior of the beam 14 is pressurized sufficiently to cause the hydraulic unit 56 to contract to a point intermediate of its maximum length, thereby causing the load suspended from the cantilevered arm 62 to be somewhat cushioned for vertical motion as it advances along the guide elements in its screeding operation.

During the screeding operation, the prime mover passes through previously deposited un-set concrete or the like. On the prime mover the regular tractor drive is used for transport and an auxiliary hydraulic drive provides a crawl speed for refinishing. Also for finishing, as mentioned previously, the frame carrying the screeding beams is partially lifted by the pneumatic cylinder 56 to provide a floating action that allows the screeding beams to follow the grade set by the side guide elements 90, 92, without applying excessive weight that would deaden the vibration or cause the elements 90,92 to be deflected.

Vibratory motion is applied to the screeding boards by means of the motor driven vibrator units 28,30. For the sake of simplicity, the means electrical or hydraulic for applying power to the units 28, is not shown.

Lateral movement of the apparatus is generally accomplished by steering the prime mover, but a degree of lateral movement of the frame 12 is accomplished by movement of the hydraulic cylinder 38 which is coupled to the arm element 42 which extends from the frame 12.

Movement of the cylinder of the unit 36 is accomplished by applying hydraulic fluid through input lines Safety: Operator is seated on prime mover instead of standing at end of a tractor where he is exposed to traftie in the adjacent lane. Screeding boards can be raised to convenient height for adjustments, cleaning or loading on trailer. Manual lifting and shoving of beams is eliminated.

Improved Quality: Less weight on guide elements and better operator visibility, with fingertip control of travel speed, vibration and beam height, all contribute to a smoother finish that is truer to grade.

Efficiency: Because guide elements do not support weight of the machine, they can be cheaper (wood instead of steel), therefore expendable, eliminating haul- 4 ing and cleaning.

Less work is required at start because grout is deposited at end of lane before finisher moves in.

Accessibility: Open ends and ability to raise beams to convenient height makes modifications for curb or crown easier.

Flexibility: Elimination of end carriages and truss removes need for these difficult adjustments. Travel speed adjustments are easier and of wider range. This allows greater flexibility in number of workers, depth of pour, condition of grout, etc.

Portability: Unit is self loading and unloading onto trailer for long distance transport.

In transport gear, tractor with beams attached is easily driven from loading point to job site.

What is claimed is:

l. Screeding apparatus adapted to be carried by a prime mover having arms for raising, lowering or tilting a load, comprising a mounting plate adapted to be coupled to said arms, a rigid cantilevered arm'extending forward of said mounting plate and supported at an elevated position therefrom, a generally H-shaped frame comprising an elongated member having a transversely extending member at each end, said frame being supported from said cantilevered arm by a pneumatic cylinder coupled between said arm and said elongated member, a pair of screeder boards, said boards being flexibly coupled to the transversely extending frame members, means for vibrating said boards, means including a pressurized reservoir of gas coupled to said pneumatic cylinder for pressurizing said pneumatic cylinder, said reservoir being a part of the structure of said elongated member, a pair of bar-like coupling elements, each of said bar-like coupling elements being pivotally coupled between said mounting plate and an end of said frame, said bar-like coupling elements being generally parallel to each other, and means pivotally coupled between said mounting plate and one of said transversely extending members of said frame for effecting lateral movement of said frame with respect to said mounting plate.

2. Apparatus in accordance with claim 1, wherein said means for effecting lateral movement of said frame includes a fluid actuated cylinder pivotally coupled to said mounting plate and to a rigid arm fixedly coupled to said frame.

3. Apparatus in accordance with claim 1 wherein said pneumatic cylinder is pivotally coupled to said cantilevered arm. 

1. Screeding apparatus adapted to be carried by a prime mover having arms for raising, lowering or tilting a load, comprising a mounting plate adapted to be coupled to said arms, a rigid cantilevered arm extending forward of said mounting plate and supported at an elevated position therefrom, a generally H-shaped frame comprising an elongated member having a transversely extending member at each end, said frame being supported from said cantilevered arm by a pneumatic cylinder coupled between said arm and said elongated member, a pair of screeder boards, said boards being flexibly coupled to the transversely extending frame members, means for vibrating said boards, means including a pressurized reservoir of gas coupled to said pneumatic cylinder for pressurizing said pneumatic cylinder, said reservoir being a part of the structure of said elongated member, a pair of barlike coupling elements, each of said bar-like coupling elements being pivotally coupled between said mounting plate and an end of said frame, said bar-like coupling elements being generally parallel to each other, and means pivotally coupled between said mounting plate and one of said transversely extending members of said frame for effecting lateral movement of said frame with respect to said mounTing plate.
 2. Apparatus in accordance with claim 1, wherein said means for effecting lateral movement of said frame includes a fluid actuated cylinder pivotally coupled to said mounting plate and to a rigid arm fixedly coupled to said frame.
 3. Apparatus in accordance with claim 1 wherein said pneumatic cylinder is pivotally coupled to said cantilevered arm. 